Flu cases alone have spiked the most in the south. According to the CDC, Texas is second only to Arkansas in percentage of doctor's visits linked to the flu.

"It's definitely been a busy flu season with some severe cases," said Dr. Michael Chang, an infectious disease specialist with Memorial Hermann Texas Medical Center and UT Health.

He says the most serious cases that bring patients in to the emergency room are from dehydration, high fever and difficulty breathing.

"I think a lot of people just feel terrible, which is one thing that can help you differentiate whether you have the flu, versus some other respiratory viruses that are common right now. The flu really should knock you down," said Dr. Chang.

He adds the hospitals prepare for every winter expecting a high number of visits. And with multiple strains circulating, it's not always predictable just how bad it may be.

As for the Trujillos, they are all finally well and enjoying some fresh air at the zoo.

"This is the last day of vacation we have to do something out there," said Francia Trujillo.

Doctors predict flu season could still last 8 to 12 more weeks. It's not too late to get a flu shot, and even if you've had the flu, they say since there are different strains, the shot could still be beneficial.